Kotlin codegen breaks in multiple ways

Using io.swagger.codegen.v3:swagger-codegen-cli:3.0.18 and kotlin-server code generator, I run into multiple problems with input of codegen_failure.yaml.zip.

Problems:

1. In DeviceRenderOptions.kt, We have enum class SdkUiType(val value: kotlin.Array<kotlin.String>) which is probably because of using Handlebars {{ stuff }} instead of {{{ stuff }}} .
2. In DeviceRenderOptions.kt, Enum class SdkUiType takes in an array instead of a String as an input.
3. In PaymentMethodsRequest we have additionalData which is to be one of AdditionalDataCommon or AdditionalData3DSecure. This maps to empty data class of AnyOfPaymentMethodsRequestAdditionalData and into two unrelated data classes AdditionalDataCommon and AdditionalData3DSecure. So this won't compile either. Ideally the case would be represented in Kotlin as a sealed class AnyOfPaymentMethodsRequestAdditionalData with those subclasses.

Start with the supplied codegen_failure.yaml.zip and the kotlin-server generator templates that produce DeviceRenderOptions.kt and PaymentMethodsRequest. Compare the generated Kotlin with the three reported problems; done means the generated enum compiles with a String value and the additionalData alternatives are represented in a compilable Kotlin model.